<?php
/**
 * CakePHP(tm) : Rapid Development Framework (http://cakephp.org)
 * Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
 *
 * Licensed under The MIT License
 * For full copyright and license information, please see the LICENSE.txt
 * Redistributions of files must retain the above copyright notice.
 *
 * @copyright     Copyright (c) Cake Software Foundation, Inc. (http://cakefoundation.org)
 * @link          http://cakephp.org CakePHP(tm) Project
 * @package       Cake.View
 * @since         CakePHP(tm) v 0.2.9
 * @license       MIT License (http://www.opensource.org/licenses/mit-license.php)
 */

App::uses('Router', 'Routing');
App::uses('Hash', 'Utility');

/**
 * Abstract base class for all other Helpers in CakePHP.
 * Provides common methods and features.
 *
 * @package       Cake.View
 */
class Helper extends Object
{

    /**
     * Settings for this helper.
     *
     * @var array
     */
    public $settings = array();

    /**
     * List of helpers used by this helper
     *
     * @var array
     */
    public $helpers = array();

    /**
     * A helper lookup table used to lazy load helper objects.
     *
     * @var array
     */
    protected $_helperMap = array();

    /**
     * The current theme name if any.
     *
     * @var string
     */
    public $theme = null;

    /**
     * Request object
     *
     * @var CakeRequest
     */
    public $request = null;

    /**
     * Plugin path
     *
     * @var string
     */
    public $plugin = null;

    /**
     * Holds the fields array('field_name' => array('type' => 'string', 'length' => 100),
     * primaryKey and validates array('field_name')
     *
     * @var array
     */
    public $fieldset = array();

    /**
     * Holds tag templates.
     *
     * @var array
     */
    public $tags = array();

    /**
     * Holds the content to be cleaned.
     *
     * @var mixed
     */
    protected $_tainted = null;

    /**
     * Holds the cleaned content.
     *
     * @var mixed
     */
    protected $_cleaned = null;

    /**
     * The View instance this helper is attached to
     *
     * @var View
     */
    protected $_View;

    /**
     * A list of strings that should be treated as suffixes, or
     * sub inputs for a parent input. This is used for date/time
     * inputs primarily.
     *
     * @var array
     */
    protected $_fieldSuffixes = array(
        'year', 'month', 'day', 'hour', 'min', 'second', 'meridian'
    );

    /**
     * The name of the current model entities are in scope of.
     *
     * @see Helper::setEntity()
     * @var string
     */
    protected $_modelScope;

    /**
     * The name of the current model association entities are in scope of.
     *
     * @see Helper::setEntity()
     * @var string
     */
    protected $_association;

    /**
     * The dot separated list of elements the current field entity is for.
     *
     * @see Helper::setEntity()
     * @var string
     */
    protected $_entityPath;

    /**
     * Minimized attributes
     *
     * @var array
     */
    protected $_minimizedAttributes = array(
        'compact', 'checked', 'declare', 'readonly', 'disabled', 'selected',
        'defer', 'ismap', 'nohref', 'noshade', 'nowrap', 'multiple', 'noresize',
        'autoplay', 'controls', 'loop', 'muted', 'required', 'novalidate', 'formnovalidate'
    );

    /**
     * Format to attribute
     *
     * @var string
     */
    protected $_attributeFormat = '%s="%s"';

    /**
     * Format to attribute
     *
     * @var string
     */
    protected $_minimizedAttributeFormat = '%s="%s"';

    /**
     * Default Constructor
     *
     * @param View $View The View this helper is being attached to.
     * @param array $settings Configuration settings for the helper.
     */
    public function __construct(View $View, $settings = array())
    {
        $this->_View = $View;
        $this->request = $View->request;
        if ($settings) {
            $this->settings = Hash::merge($this->settings, $settings);
        }
        if (!empty($this->helpers)) {
            $this->_helperMap = ObjectCollection::normalizeObjectArray($this->helpers);
        }
    }

    /**
     * Provide non fatal errors on missing method calls.
     *
     * @param string $method Method to invoke
     * @param array $params Array of params for the method.
     * @return void
     */
    public function __call($method, $params)
    {
        trigger_error(__d('cake_dev', 'Method %1$s::%2$s does not exist', get_class($this), $method), E_USER_WARNING);
    }

    /**
     * Lazy loads helpers. Provides access to deprecated request properties as well.
     *
     * @param string $name Name of the property being accessed.
     * @return mixed Helper or property found at $name
     */
    public function __get($name)
    {
        if (isset($this->_helperMap[$name]) && !isset($this->{$name})) {
            $settings = array_merge((array)$this->_helperMap[$name]['settings'], array('enabled' => false));
            $this->{$name} = $this->_View->loadHelper($this->_helperMap[$name]['class'], $settings);
        }
        if (isset($this->{$name})) {
            return $this->{$name};
        }
        switch ($name) {
            case 'base':
            case 'here':
            case 'webroot':
            case 'data':
                return $this->request->{$name};
            case 'action':
                return isset($this->request->params['action']) ? $this->request->params['action'] : '';
            case 'params':
                return $this->request;
        }
    }

    /**
     * Provides backwards compatibility access for setting values to the request object.
     *
     * @param string $name Name of the property being accessed.
     * @param mixed $value
     * @return mixed Return the $value
     */
    public function __set($name, $value)
    {
        switch ($name) {
            case 'base':
            case 'here':
            case 'webroot':
            case 'data':
                return $this->request->{$name} = $value;
            case 'action':
                return $this->request->params['action'] = $value;
        }
        return $this->{$name} = $value;
    }

    /**
     * Finds URL for specified action.
     *
     * Returns a URL pointing at the provided parameters.
     *
     * @param string|array $url Either a relative string url like `/products/view/23` or
     *    an array of url parameters. Using an array for urls will allow you to leverage
     *    the reverse routing features of CakePHP.
     * @param boolean $full If true, the full base URL will be prepended to the result
     * @return string  Full translated URL with base path.
     * @link http://book.cakephp.org/2.0/en/views/helpers.html
     */
    public function url($url = null, $full = false)
    {
        return h(Router::url($url, $full));
    }

    /**
     * Checks if a file exists when theme is used, if no file is found default location is returned
     *
     * @param string $file The file to create a webroot path to.
     * @return string Web accessible path to file.
     */
    public function webroot($file)
    {
        $asset = explode('?', $file);
        $asset[1] = isset($asset[1]) ? '?' . $asset[1] : null;
        $webPath = "{$this->request->webroot}" . $asset[0];
        $file = $asset[0];

        if (!empty($this->theme)) {
            $file = trim($file, '/');
            $theme = $this->theme . '/';

            if (DS === '\\') {
                $file = str_replace('/', '\\', $file);
            }

            if (file_exists(Configure::read('App.www_root') . 'theme' . DS . $this->theme . DS . $file)) {
                $webPath = "{$this->request->webroot}theme/" . $theme . $asset[0];
            } else {
                $themePath = App::themePath($this->theme);
                $path = $themePath . 'webroot' . DS . $file;
                if (file_exists($path)) {
                    $webPath = "{$this->request->webroot}theme/" . $theme . $asset[0];
                }
            }
        }
        if (strpos($webPath, '//') !== false) {
            return str_replace('//', '/', $webPath . $asset[1]);
        }
        return $webPath . $asset[1];
    }

    /**
     * Generate url for given asset file. Depending on options passed provides full url with domain name.
     * Also calls Helper::assetTimestamp() to add timestamp to local files
     *
     * @param string|array Path string or url array
     * @param array $options Options array. Possible keys:
     *   `fullBase` Return full url with domain name
     *   `pathPrefix` Path prefix for relative urls
     *   `ext` Asset extension to append
     *   `plugin` False value will prevent parsing path as a plugin
     * @return string Generated url
     */
    public function assetUrl($path, $options = array())
    {
        if (is_array($path)) {
            return $this->url($path, !empty($options['fullBase']));
        }
        if (strpos($path, '://') !== false) {
            return $path;
        }
        if (!array_key_exists('plugin', $options) || $options['plugin'] !== false) {
            list($plugin, $path) = $this->_View->pluginSplit($path, false);
        }
        if (!empty($options['pathPrefix']) && $path[0] !== '/') {
            $path = $options['pathPrefix'] . $path;
        }
        if (
            !empty($options['ext']) &&
            strpos($path, '?') === false &&
            substr($path, -strlen($options['ext'])) !== $options['ext']
        ) {
            $path .= $options['ext'];
        }
        if (isset($plugin)) {
            $path = Inflector::underscore($plugin) . '/' . $path;
        }
        $path = $this->_encodeUrl($this->assetTimestamp($this->webroot($path)));

        if (!empty($options['fullBase'])) {
            $base = $this->url('/', true);
            $len = strlen($this->request->webroot);
            if ($len) {
                $base = substr($base, 0, -$len);
            }
            $path = $base . $path;
        }
        return $path;
    }

    /**
     * Encodes a URL for use in HTML attributes.
     *
     * @param string $url The url to encode.
     * @return string The url encoded for both URL & HTML contexts.
     */
    protected function _encodeUrl($url)
    {
        $path = parse_url($url, PHP_URL_PATH);
        $encoded = implode('/', array_map(
            'rawurlencode',
            explode('/', $path)
        ));
        return h(str_replace($path, $encoded, $url));
    }

    /**
     * Adds a timestamp to a file based resource based on the value of `Asset.timestamp` in
     * Configure. If Asset.timestamp is true and debug > 0, or Asset.timestamp === 'force'
     * a timestamp will be added.
     *
     * @param string $path The file path to timestamp, the path must be inside WWW_ROOT
     * @return string Path with a timestamp added, or not.
     */
    public function assetTimestamp($path)
    {
        $stamp = Configure::read('Asset.timestamp');
        $timestampEnabled = $stamp === 'force' || ($stamp === true && Configure::read('debug') > 0);
        if ($timestampEnabled && strpos($path, '?') === false) {
            $filepath = preg_replace('/^' . preg_quote($this->request->webroot, '/') . '/', '', $path);
            $webrootPath = WWW_ROOT . str_replace('/', DS, $filepath);
            if (file_exists($webrootPath)) {
                //@codingStandardsIgnoreStart
                return $path . '?' . @filemtime($webrootPath);
                //@codingStandardsIgnoreEnd
            }
            $segments = explode('/', ltrim($filepath, '/'));
            if ($segments[0] === 'theme') {
                $theme = $segments[1];
                unset($segments[0], $segments[1]);
                $themePath = App::themePath($theme) . 'webroot' . DS . implode(DS, $segments);
                //@codingStandardsIgnoreStart
                return $path . '?' . @filemtime($themePath);
                //@codingStandardsIgnoreEnd
            } else {
                $plugin = Inflector::camelize($segments[0]);
                if (CakePlugin::loaded($plugin)) {
                    unset($segments[0]);
                    $pluginPath = CakePlugin::path($plugin) . 'webroot' . DS . implode(DS, $segments);
                    //@codingStandardsIgnoreStart
                    return $path . '?' . @filemtime($pluginPath);
                    //@codingStandardsIgnoreEnd
                }
            }
        }
        return $path;
    }

    /**
     * Used to remove harmful tags from content. Removes a number of well known XSS attacks
     * from content. However, is not guaranteed to remove all possibilities. Escaping
     * content is the best way to prevent all possible attacks.
     *
     * @param string|array $output Either an array of strings to clean or a single string to clean.
     * @return string|array cleaned content for output
     */
    public function clean($output)
    {
        $this->_reset();
        if (empty($output)) {
            return null;
        }
        if (is_array($output)) {
            foreach ($output as $key => $value) {
                $return[$key] = $this->clean($value);
            }
            return $return;
        }
        $this->_tainted = $output;
        $this->_clean();
        return $this->_cleaned;
    }

    /**
     * Returns a space-delimited string with items of the $options array. If a key
     * of $options array happens to be one of those listed in `Helper::$_minimizedAttributes`
     *
     * And its value is one of:
     *
     * - '1' (string)
     * - 1 (integer)
     * - true (boolean)
     * - 'true' (string)
     *
     * Then the value will be reset to be identical with key's name.
     * If the value is not one of these 3, the parameter is not output.
     *
     * 'escape' is a special option in that it controls the conversion of
     *  attributes to their html-entity encoded equivalents. Set to false to disable html-encoding.
     *
     * If value for any option key is set to `null` or `false`, that option will be excluded from output.
     *
     * @param array $options Array of options.
     * @param array $exclude Array of options to be excluded, the options here will not be part of the return.
     * @param string $insertBefore String to be inserted before options.
     * @param string $insertAfter String to be inserted after options.
     * @return string Composed attributes.
     * @deprecated This method will be moved to HtmlHelper in 3.0
     */
    protected function _parseAttributes($options, $exclude = null, $insertBefore = ' ', $insertAfter = null)
    {
        if (!is_string($options)) {
            $options = (array)$options + array('escape' => true);

            if (!is_array($exclude)) {
                $exclude = array();
            }

            $exclude = array('escape' => true) + array_flip($exclude);
            $escape = $options['escape'];
            $attributes = array();

            foreach ($options as $key => $value) {
                if (!isset($exclude[$key]) && $value !== false && $value !== null) {
                    $attributes[] = $this->_formatAttribute($key, $value, $escape);
                }
            }
            $out = implode(' ', $attributes);
        } else {
            $out = $options;
        }
        return $out ? $insertBefore . $out . $insertAfter : '';
    }

    /**
     * Formats an individual attribute, and returns the string value of the composed attribute.
     * Works with minimized attributes that have the same value as their name such as 'disabled' and 'checked'
     *
     * @param string $key The name of the attribute to create
     * @param string $value The value of the attribute to create.
     * @param boolean $escape Define if the value must be escaped
     * @return string The composed attribute.
     * @deprecated This method will be moved to HtmlHelper in 3.0
     */
    protected function _formatAttribute($key, $value, $escape = true)
    {
        if (is_array($value)) {
            $value = implode(' ', $value);
        }
        if (is_numeric($key)) {
            return sprintf($this->_minimizedAttributeFormat, $value, $value);
        }
        $truthy = array(1, '1', true, 'true', $key);
        $isMinimized = in_array($key, $this->_minimizedAttributes);
        if ($isMinimized && in_array($value, $truthy, true)) {
            return sprintf($this->_minimizedAttributeFormat, $key, $key);
        }
        if ($isMinimized) {
            return '';
        }
        return sprintf($this->_attributeFormat, $key, ($escape ? h($value) : $value));
    }

    /**
     * Sets this helper's model and field properties to the dot-separated value-pair in $entity.
     *
     * @param string $entity A field name, like "ModelName.fieldName" or "ModelName.ID.fieldName"
     * @param boolean $setScope Sets the view scope to the model specified in $tagValue
     * @return void
     */
    public function setEntity($entity, $setScope = false)
    {
        if ($entity === null) {
            $this->_modelScope = false;
        }
        if ($setScope === true) {
            $this->_modelScope = $entity;
        }
        $parts = array_values(Hash::filter(explode('.', $entity)));
        if (empty($parts)) {
            return;
        }
        $count = count($parts);
        $lastPart = isset($parts[$count - 1]) ? $parts[$count - 1] : null;

        // Either 'body' or 'date.month' type inputs.
        if (
            ($count === 1 && $this->_modelScope && !$setScope) ||
            (
                $count === 2 &&
                in_array($lastPart, $this->_fieldSuffixes) &&
                $this->_modelScope &&
                $parts[0] !== $this->_modelScope
            )
        ) {
            $entity = $this->_modelScope . '.' . $entity;
        }

        // 0.name, 0.created.month style inputs. Excludes inputs with the modelScope in them.
        if (
            $count >= 2 &&
            is_numeric($parts[0]) &&
            !is_numeric($parts[1]) &&
            $this->_modelScope &&
            strpos($entity, $this->_modelScope) === false
        ) {
            $entity = $this->_modelScope . '.' . $entity;
        }

        $this->_association = null;

        $isHabtm = (
            isset($this->fieldset[$this->_modelScope]['fields'][$parts[0]]['type']) &&
                $this->fieldset[$this->_modelScope]['fields'][$parts[0]]['type'] === 'multiple'
        );

        // habtm models are special
        if ($count === 1 && $isHabtm) {
            $this->_association = $parts[0];
            $entity = $parts[0] . '.' . $parts[0];
        } else {
            // check for associated model.
            $reversed = array_reverse($parts);
            foreach ($reversed as $i => $part) {
                if ($i > 0 && preg_match('/^[A-Z]/', $part)) {
                    $this->_association = $part;
                    break;
                }
            }
        }
        $this->_entityPath = $entity;
    }

    /**
     * Returns the entity reference of the current context as an array of identity parts
     *
     * @return array An array containing the identity elements of an entity
     */
    public function entity()
    {
        return explode('.', $this->_entityPath);
    }

    /**
     * Gets the currently-used model of the rendering context.
     *
     * @return string
     */
    public function model()
    {
        if ($this->_association) {
            return $this->_association;
        }
        return $this->_modelScope;
    }

    /**
     * Gets the currently-used model field of the rendering context.
     * Strips off field suffixes such as year, month, day, hour, min, meridian
     * when the current entity is longer than 2 elements.
     *
     * @return string
     */
    public function field()
    {
        $entity = $this->entity();
        $count = count($entity);
        $last = $entity[$count - 1];
        if ($count > 2 && in_array($last, $this->_fieldSuffixes)) {
            $last = isset($entity[$count - 2]) ? $entity[$count - 2] : null;
        }
        return $last;
    }

    /**
     * Generates a DOM ID for the selected element, if one is not set.
     * Uses the current View::entity() settings to generate a CamelCased id attribute.
     *
     * @param array|string $options Either an array of html attributes to add $id into, or a string
     *   with a view entity path to get a domId for.
     * @param string $id The name of the 'id' attribute.
     * @return mixed If $options was an array, an array will be returned with $id set. If a string
     *   was supplied, a string will be returned.
     */
    public function domId($options = null, $id = 'id')
    {
        if (is_array($options) && array_key_exists($id, $options) && $options[$id] === null) {
            unset($options[$id]);
            return $options;
        } elseif (!is_array($options) && $options !== null) {
            $this->setEntity($options);
            return $this->domId();
        }

        $entity = $this->entity();
        $model = array_shift($entity);
        $dom = $model . implode('', array_map(array('Inflector', 'camelize'), $entity));

        if (is_array($options) && !array_key_exists($id, $options)) {
            $options[$id] = $dom;
        } elseif ($options === null) {
            return $dom;
        }
        return $options;
    }

    /**
     * Gets the input field name for the current tag. Creates input name attributes
     * using CakePHP's data[Model][field] formatting.
     *
     * @param array|string $options If an array, should be an array of attributes that $key needs to be added to.
     *   If a string or null, will be used as the View entity.
     * @param string $field
     * @param string $key The name of the attribute to be set, defaults to 'name'
     * @return mixed If an array was given for $options, an array with $key set will be returned.
     *   If a string was supplied a string will be returned.
     */
    protected function _name($options = array(), $field = null, $key = 'name')
    {
        if ($options === null) {
            $options = array();
        } elseif (is_string($options)) {
            $field = $options;
            $options = 0;
        }

        if (!empty($field)) {
            $this->setEntity($field);
        }

        if (is_array($options) && array_key_exists($key, $options)) {
            return $options;
        }

        switch ($field) {
            case '_method':
                $name = $field;
                break;
            default:
                $name = 'data[' . implode('][', $this->entity()) . ']';
                break;
        }

        if (is_array($options)) {
            $options[$key] = $name;
            return $options;
        } else {
            return $name;
        }
    }

    /**
     * Gets the data for the current tag
     *
     * @param array|string $options If an array, should be an array of attributes that $key needs to be added to.
     *   If a string or null, will be used as the View entity.
     * @param string $field
     * @param string $key The name of the attribute to be set, defaults to 'value'
     * @return mixed If an array was given for $options, an array with $key set will be returned.
     *   If a string was supplied a string will be returned.
     */
    public function value($options = array(), $field = null, $key = 'value')
    {
        if ($options === null) {
            $options = array();
        } elseif (is_string($options)) {
            $field = $options;
            $options = 0;
        }

        if (is_array($options) && isset($options[$key])) {
            return $options;
        }

        if (!empty($field)) {
            $this->setEntity($field);
        }
        $result = null;
        $data = $this->request->data;

        $entity = $this->entity();
        if (!empty($data) && is_array($data) && !empty($entity)) {
            $result = Hash::get($data, implode('.', $entity));
        }

        $habtmKey = $this->field();
        if (empty($result) && isset($data[$habtmKey][$habtmKey]) && is_array($data[$habtmKey])) {
            $result = $data[$habtmKey][$habtmKey];
        } elseif (empty($result) && isset($data[$habtmKey]) && is_array($data[$habtmKey])) {
            if (ClassRegistry::isKeySet($habtmKey)) {
                $model = ClassRegistry::getObject($habtmKey);
                $result = $this->_selectedArray($data[$habtmKey], $model->primaryKey);
            }
        }

        if (is_array($options)) {
            if ($result === null && isset($options['default'])) {
                $result = $options['default'];
            }
            unset($options['default']);
        }

        if (is_array($options)) {
            $options[$key] = $result;
            return $options;
        } else {
            return $result;
        }
    }

    /**
     * Sets the defaults for an input tag. Will set the
     * name, value, and id attributes for an array of html attributes.
     *
     * @param string $field The field name to initialize.
     * @param array $options Array of options to use while initializing an input field.
     * @return array Array options for the form input.
     */
    protected function _initInputField($field, $options = array())
    {
        if ($field !== null) {
            $this->setEntity($field);
        }
        $options = (array)$options;
        $options = $this->_name($options);
        $options = $this->value($options);
        $options = $this->domId($options);
        return $options;
    }

    /**
     * Adds the given class to the element options
     *
     * @param array $options Array options/attributes to add a class to
     * @param string $class The classname being added.
     * @param string $key the key to use for class.
     * @return array Array of options with $key set.
     */
    public function addClass($options = array(), $class = null, $key = 'class')
    {
        if (isset($options[$key]) && trim($options[$key])) {
            $options[$key] .= ' ' . $class;
        } else {
            $options[$key] = $class;
        }
        return $options;
    }

    /**
     * Returns a string generated by a helper method
     *
     * This method can be overridden in subclasses to do generalized output post-processing
     *
     * @param string $str String to be output.
     * @return string
     * @deprecated This method will be removed in future versions.
     */
    public function output($str)
    {
        return $str;
    }

    /**
     * Before render callback. beforeRender is called before the view file is rendered.
     *
     * Overridden in subclasses.
     *
     * @param string $viewFile The view file that is going to be rendered
     * @return void
     */
    public function beforeRender($viewFile)
    {
    }

    /**
     * After render callback. afterRender is called after the view file is rendered
     * but before the layout has been rendered.
     *
     * Overridden in subclasses.
     *
     * @param string $viewFile The view file that was rendered.
     * @return void
     */
    public function afterRender($viewFile)
    {
    }

    /**
     * Before layout callback. beforeLayout is called before the layout is rendered.
     *
     * Overridden in subclasses.
     *
     * @param string $layoutFile The layout about to be rendered.
     * @return void
     */
    public function beforeLayout($layoutFile)
    {
    }

    /**
     * After layout callback. afterLayout is called after the layout has rendered.
     *
     * Overridden in subclasses.
     *
     * @param string $layoutFile The layout file that was rendered.
     * @return void
     */
    public function afterLayout($layoutFile)
    {
    }

    /**
     * Before render file callback.
     * Called before any view fragment is rendered.
     *
     * Overridden in subclasses.
     *
     * @param string $viewFile The file about to be rendered.
     * @return void
     */
    public function beforeRenderFile($viewfile)
    {
    }

    /**
     * After render file callback.
     * Called after any view fragment is rendered.
     *
     * Overridden in subclasses.
     *
     * @param string $viewFile The file just be rendered.
     * @param string $content The content that was rendered.
     * @return void
     */
    public function afterRenderFile($viewfile, $content)
    {
    }

    /**
     * Transforms a recordset from a hasAndBelongsToMany association to a list of selected
     * options for a multiple select element
     *
     * @param string|array $data
     * @param string $key
     * @return array
     */
    protected function _selectedArray($data, $key = 'id')
    {
        if (!is_array($data)) {
            $model = $data;
            if (!empty($this->request->data[$model][$model])) {
                return $this->request->data[$model][$model];
            }
            if (!empty($this->request->data[$model])) {
                $data = $this->request->data[$model];
            }
        }
        $array = array();
        if (!empty($data)) {
            foreach ($data as $row) {
                if (isset($row[$key])) {
                    $array[$row[$key]] = $row[$key];
                }
            }
        }
        return empty($array) ? null : $array;
    }

    /**
     * Resets the vars used by Helper::clean() to null
     *
     * @return void
     */
    protected function _reset()
    {
        $this->_tainted = null;
        $this->_cleaned = null;
    }

    /**
     * Removes harmful content from output
     *
     * @return void
     */
    protected function _clean()
    {
        if (get_magic_quotes_gpc()) {
            $this->_cleaned = stripslashes($this->_tainted);
        } else {
            $this->_cleaned = $this->_tainted;
        }

        $this->_cleaned = str_replace(array("&amp;", "&lt;", "&gt;"), array("&amp;amp;", "&amp;lt;", "&amp;gt;"), $this->_cleaned);
        $this->_cleaned = preg_replace('#(&\#*\w+)[\x00-\x20]+;#u', "$1;", $this->_cleaned);
        $this->_cleaned = preg_replace('#(&\#x*)([0-9A-F]+);*#iu', "$1$2;", $this->_cleaned);
        $this->_cleaned = html_entity_decode($this->_cleaned, ENT_COMPAT, "UTF-8");
        $this->_cleaned = preg_replace('#(<[^>]+[\x00-\x20\"\'\/])(on|xmlns)[^>]*>#iUu', "$1>", $this->_cleaned);
        $this->_cleaned = preg_replace('#([a-z]*)[\x00-\x20]*=[\x00-\x20]*([\`\'\"]*)[\\x00-\x20]*j[\x00-\x20]*a[\x00-\x20]*v[\x00-\x20]*a[\x00-\x20]*s[\x00-\x20]*c[\x00-\x20]*r[\x00-\x20]*i[\x00-\x20]*p[\x00-\x20]*t[\x00-\x20]*:#iUu', '$1=$2nojavascript...', $this->_cleaned);
        $this->_cleaned = preg_replace('#([a-z]*)[\x00-\x20]*=([\'\"]*)[\x00-\x20]*v[\x00-\x20]*b[\x00-\x20]*s[\x00-\x20]*c[\x00-\x20]*r[\x00-\x20]*i[\x00-\x20]*p[\x00-\x20]*t[\x00-\x20]*:#iUu', '$1=$2novbscript...', $this->_cleaned);
        $this->_cleaned = preg_replace('#([a-z]*)[\x00-\x20]*=*([\'\"]*)[\x00-\x20]*-moz-binding[\x00-\x20]*:#iUu', '$1=$2nomozbinding...', $this->_cleaned);
        $this->_cleaned = preg_replace('#([a-z]*)[\x00-\x20]*=([\'\"]*)[\x00-\x20]*data[\x00-\x20]*:#Uu', '$1=$2nodata...', $this->_cleaned);
        $this->_cleaned = preg_replace('#(<[^>]+)style[\x00-\x20]*=[\x00-\x20]*([\`\'\"]*).*expression[\x00-\x20]*\([^>]*>#iU', "$1>", $this->_cleaned);
        $this->_cleaned = preg_replace('#(<[^>]+)style[\x00-\x20]*=[\x00-\x20]*([\`\'\"]*).*behaviour[\x00-\x20]*\([^>]*>#iU', "$1>", $this->_cleaned);
        $this->_cleaned = preg_replace('#(<[^>]+)style[\x00-\x20]*=[\x00-\x20]*([\`\'\"]*).*s[\x00-\x20]*c[\x00-\x20]*r[\x00-\x20]*i[\x00-\x20]*p[\x00-\x20]*t[\x00-\x20]*:*[^>]*>#iUu', "$1>", $this->_cleaned);
        $this->_cleaned = preg_replace('#</*\w+:\w[^>]*>#i', "", $this->_cleaned);
        do {
            $oldstring = $this->_cleaned;
            $this->_cleaned = preg_replace('#</*(applet|meta|xml|blink|link|style|script|embed|object|iframe|frame|frameset|ilayer|layer|bgsound|title|base)[^>]*>#i', "", $this->_cleaned);
        } while ($oldstring != $this->_cleaned);
        $this->_cleaned = str_replace(array("&amp;", "&lt;", "&gt;"), array("&amp;amp;", "&amp;lt;", "&amp;gt;"), $this->_cleaned);
    }

}
